Paso Robles vintners, in their quest to show the diversity of the area, have submitted two separate proposals to federal regulators, requesting permission to divvy the area into subappellations.

But there's a squabble over how the boundaries should be drawn.

Jerry Lohr, head of the Paso Robles AVA Committee, which is proposing that the 614,000-acre American Viticultural Area eventually be sliced into 11 subappellations, says his committee's plan makes the most sense.

"Each one of these 11 areas has a different soil and a different microclimate, which creates a different flavor," he says, adding that this type of branding would be advantageous to consumers looking for a specific style of wine.

The committee, which hired UC Davis geology Professor Deborah Elliott-Fisk to help determine the divisions, maintains that each area has its own unique weather conditions and geography.

Before the AVA committee submitted its proposal to the Alcohol and Tobacco Tax and Trade Bureau, another plan was already under way. Headed by Peachy Canyon's Doug Beckett, wineries located on the west side of the Salinas River and U.S. Highway 101 want their own 179,622-acre subregion. That faction says that the fruit grown on the west side is so distinct that it deserves its own designation.

But the plan has become controversial and some have even called it divisive.

Now, onetime backers of Beckett's petition are pulling their support. Justin Baldwin, owner of Justin Vineyards & Winery, was one of the original proponents of the Westside proposal, but is now endorsing the idea for 11 subappellations because he says it's the better of the two plans.

"There really are differences here," he says. "And we should point them out. It will take consumers a minimum of 10 to 20 years to notice, but it will help growers selling their grapes to distinguish themselves and get more money for their product. It just raises the tide."

Thomas Rice, a soil scientist from Cal Poly who consulted on the Westside plan, has also questioned the proposal. He recently wrote the TTB to complain that his analysis in the project had been "inaccurately quoted" and "some erroneous conclusions" had been stated in the final petition. He urged the board to reject the plan.

Gary Eberle, of Eberle Winery, says the Westside proposal defies logic. "The same conditions exist on both sides of the river," Eberle says. "If you're going to do something like this why not make it real. At least the proposal for 11 subappellations is based on true science. I don't know that they're perfect, but there is some sense to it."

Eberle says if it was up to him, he'd forgo subregions altogether.

"Most people can't even name 5 of Napa's 14 subappellations," he says. "I think some people are having trouble selling their wine and they're grasping at straws."